1. Field
The present disclosure relates generally to an electrosurgical system and method and, more specifically, to a system and method for ablating impenetrable abnormal tissue.
2. Description of the Related Art
The use of radiofrequency electrodes for ablation of tissue in a patient's body is known. In a typical situation, a radiofrequency electrode having an elongated, cylindrical shaft with a portion of its external surface insulated is inserted into the patient's body. The electrode typically has an exposed conductive tip, which is used to contact body tissue in the region where the heat lesion or ablation is desired. The electrode is connected to a radiofrequency power source that provides radiofrequency voltage to the electrode, which, in turn, transmits the radiofrequency current into the tissue near its exposed conductive tip. This current usually returns to the power source through a return electrode, which may comprise a large area conductive contact connected to an external portion of the patient's body. This configuration has been described in various scientific articles, such as, for example, a research paper by Cosman, et al., entitled “Theoretical Aspects of Radiofrequency Lesions in the Dorsal Root Entry Zone,” Neurosurgery, December 1984, Vol. 15, No. 6, pp 945-950, and a research paper by Goldberg, et al. entitled “Tissue Ablation with Radiofrequency: Effective Probe Size, Gauge, Duration, and Temperature and Lesion Volume” Acad Radio., 1995, Vol. 2, No. 5, pp 399-404. Radiofrequency lesion generators and electrode systems such as those described above are commercially available from Radionics, Inc., located in Burlington, Mass.
It is also known to use radiofrequency electrodes to ablate tumors. However, certain types of tumors, such as some solid tissue tumors typically cannot be easily penetrated with medical instruments (e.g., biopsy needles, electrodes, etc.) and therefore cannot be directly ablated. Conventional practices to solve this issue involve ablating healthy tissue surrounding the tumors, which tend to ablate the impenetrable tumors in the process. Such procedures have undesirable consequences, such as delocalized damage to surrounding healthy tissue.